China killed or imprisoned CIA sources to stop US spying

A new NYT report details how the Chinese government thwarted the CIA's intelligence gathering operations by killing or imprisoning 18 to 20 CIA spies or sources over a two-year period starting in 2010.

The details: "From the final weeks of 2010 through the end of 2012, according to former American officials, the Chinese killed at least a dozen of the C.I.A.'s sources. According to three of the officials, one was shot in front of his colleagues in the courtyard of a government building — a message to others who might have been working for the C.I.A."

Why it matters: This shows the sophistication of the Chinese government's spy services (similar to Russia) and how successful China is at squashing the United States' spying efforts. Furthermore, it demonstrates how difficult it continues to be for the US to carry out counterespionage investigations in foreign nations — and the CIA views its spying efforts in China one of its top priorities.

How China's efforts were discovered, per NYT:

• The quality of information the CIA was receiving about China was "the best it had been for years" in early 2010, but come 2011 the information slowed and the CIA realized it was quickly losing sources in China.
• The CIA and FBI launched a joint investigation into its spying operations in Beijing. They called the top-secret investigation "Honey Badger."
• More sources continued to disappear, so Honey Badger became more urgent.
• "Some investigators believed the Chinese had cracked the encrypted method that the C.I.A. used to communicate with its assets. Others suspected a traitor in the C.I.A."
• The suspect: A Chinese-American who had left the CIA shortly before the CIA's sources began vanishing.
• "Some investigators believed he had become disgruntled and had begun spying for China. One official said the man had access to the identities of C.I.A. informants and fit all the indicators on a matrix used to identify espionage threats."
• By 2013, the CIA and FBI determined that China's previous success in finding and stopping the CIA sources had been thwarted, though it is not clear how their efforts were blunted.